Friction shock absorber for railway car trucks



Dec. 5, 1950 G. E. DATH 2,532,358

FRICTION SHOCK ABSORBER FOR RAILWAY CAR TRUCKS Filed Oct. 25, 1948 2 Sheets-Sheet 1 Dec. 5, 1950 5, BATH 2,532,358

FRICTION SHOCK ABSORBER FOR RAILWAY CAR TRUCKS Filed Oct. 25, 1948 "2 Sheets-Sheet .2

Patented Dec. 5, 1950 FRICTION SHOCK ABSORBER FOR RAILWAY GAR TRUCKS George E. Bath, Mokena, 111., assignor to W. H.

Miner, Inc., Chicago, Ill., a corporation of Dela- Ware Application October 25, 1948, Serial No. 56,350

6 Claims.

This invention relates to improvements in friction shock absorbers for snubbing the action. of railway car truck springs.

One object of the invention is to provide a friction shock absorber of the character indicated comprising top and bottom friction posts, an intermediate friction shoe member with which the posts have lengthwise sliding frictional engagement, and top and bottom springs reacting between the shoe member and posts for opposing relative lengthwise movement of the posts with respect to the shoe member, wherein the posts are held in tight frictional engagement with the shoe by resilient spring means.

A further object of the invention is to provide a mechanism as set forth in the preceding paragraph wherein the tight frictional engagement between the posts and the shoe member is provided by springs which oppose relative movement of the same, the springs being in the form of helical coils surrounding the posts and shoe member and distorted to press laterally inwardly on the shoe member and each post at respectively opposite sides of the mechanism to force the same together.

Other objects of the invention will more clearly appear from the description and claims hereinafter following.

In the accompanying drawings forming a part of this specification, Figure 1 is a side elevational view of my improved shock absorber, showing the springs in transverse vertical section. Figure 2 is a top plan view of the bottom friction post shown in Figure 1. Figure 3 is a central, transverse, vertical sectional view of Figure l with the top friction post omitted, the section corresponding substantially to the line 3-3 of Figure 4. Figure 4 is a top plan view of the friction shoe shown in Figure 1. Figure 5 is a side elevational view of Figure 2, looking from left to right in said figure. Figure 6 is a side elevational view of the canted or inclined coil spring employed at the bottom of my improved shock absorber. Figure '7 is a side elevational view of the canted or inclined coil spring employed at the top of the shock absorber.

My improved shock absorber, as shown in the drawings, comprises broadly top and bottom follower plates A and B, vertically disposed top and bottom friction posts C and D extending from the follower plates A and B, respectively, an intermediate friction shoe member E, a top helical coil spring F surrounding the top post and the upper end portion of the: friction shoe member E and opposing relative approach of the same, and a s relatively heavy plate portion l9, having a lengthwise extending fiat friction surface I I on its inner side. As shown, the friction surfaces llll of the two posts C and D are in vertical alignment and face in the same direction. At the outer end,

each post has a laterally inwardly projecting lug E2 on the inner side thereof for a purpose hereinafter described. Each post C and D has a cylindrical base portion it at the end thereof where it merges with the corresponding follower plate. A stop lug M for the tang at the outer end of the corresponding spring F or G is provided on each follower plate A and B, extending radially outwardly from the base portion is of the corresponding post. As clearly shown in Figure l, the stop lugs I el i of the top and bottom posts are preferably located at the right hand side of the mechanism.

The friction shoe member E is in the form of a block having a vertical opening I5 therethrough into which the top and bottom friction posts C and D extend. The member E has a laterally, outwardly projecting, annular flange midway between its top and bottom ends forming a follower portion 16. The top and bottom sections of the shoe member E, which project from the follower portion !5, have cylindrical base portions l'i-l'i which merge with the follower portion l5, these cylindrical base portions being of smaller diameter than the follower portion. At the right hand side thereof, as shown in Figures 1, 3, and 4, the top and bottom sections of the shoe are thickened to provide semi-cylindrical outer wall portions |8-I8 in vertical alignment with the base portions li-l'i of said sections at the corresponding side of the mechanism. At the left hand side thereof, as seen in Figure 3, the top and bottom sections of the shoe member E are extended a slight distance above and below the main body portion of said member, as indicated at Iii-l9. At the left hand side thereof, as seen in Figures 1, 3, and 4, the shoe member E has the top and bottom sections thereof reenforced by lengthwise extending webs 2fl20. Top and bottom stop lugs 2 I2l for the tangs at the inner ends of the top and bottom springs, are provided on the follower portion it of the shoe member E, extending radially outwardly from the base portions ll-l'| of the top and bottom sections of said shoe member. These stop lugs are preferably located at the right hand side of the mechanism in vertical alignment with the stop lugs l ll l of the top and bottom posts. The shoe member E has a lengthwise extending, interior, fiat friction surface 22, which is formed on the right hand side wall of the opening l5, as seen in Figure 3, engaged by the friction surfaces ll--H of the posts C and D. The surface 22 is recessed lengthwise to provide a longitudinally extending central slot 23 to accommodate the lugs I2l2 of the posts. The slot 23 is closed at the top and bottom ends, thus providing top and bottom stop shoulders 2fl-2 l with which the lugs l2-l2 of the posts are engageable to limit lengthwise expansion of the mechanism and hold the posts assembled with the shoe member.

The top and bottom helical coil springs F and G surround the posts C and D and the corresponding projecting sections of the shoe member E, the spring F having its upper end bearing on the underneath side of the top follower plate A and its lower end bearing on the upper side of the follower portion Iii of the shoe member E, and the spring G having its lower end bearing on the bottom follower plate B and its upper end bearing on the underneath side of the follower portion it of the shoe member. Both springs F and G, in the assembled condition of the mechanism, are under canting tension, that is, are formed so that they forcibly tend to assume inclined positions, the spring F toward the right and the spring G toward the left, as seen in Figure 1, thereby forcibly pressing the inner side of the upper coil of the top spring F at the right hand side of the mechanism against the base portion l3 of the top post C, and the inner side of the lower coil at the left hand side of the mechanism against the base portion ll of the upper section of the shoe member E, and forcibly pressing the inner side of the lower coil of the bottom spring G at the right hand side of the mechanism against the base portion 13 of the post D and the inner side of the upper coil at the left hand side of the mechanism against the base portion ii of the lo"er section of the shoe member E. The pressure thus exerted by the canting tension of the two springs and G forces the friction surfaces of the posts into tight frictional engagement with the friction surface of the shoe E.

In the assembled condition of the mechanism, the springs F and G are preferably under initial compression. As shown in Figures 6 and 7, the springs F and G, as manufactured, are of special design to produce the canting tension when assembled with, the posts C and D, being coiled on axes which are inclined with respect to the central vertical arses of the bases of the respective springs, the spring F being coiled in such a manner that it leans to the left when stood on its base, as illustrated in Figure '7, and the spring G in such a manner that it leans to the right, as illustra ed in Figure 6. These springs thus tend to assu e their leaning, inclined posit ons when forcibly righted by flexing the same toward their upright positions, as shown Figure 1.

In assembling th mechanism, the springs F and G are first applied to the posts C and D, the spring F being placed over the post (3 in such. a position that the tang the upper end will be in back of the lug IA of the post C, as seen in i ii Figure 1, and the tang at the lower end will be in back of the upper lug 2| of the shoe member E, when the mechanism is completely assembled, and the spring G being placed over the post D in such a manner that the tang at the lower end thereof will be in back of the lug 14 of the post D and the tang at the upper end will be in back of the lower lug 2| of the shoe member. The posts C and D, with the springs thereon, are assembled with the shoe E by engaging the springs F and G over the upper and lower sections of the shoe member E and. inserting the friction plates I -l8 of the two posts within the opening [5 of the shoe member and pressing the parts together until the lugs l2-l2 of the posts snap over the stop shoulders 2424 of the shoe member and engage Within the slot 23. The posts and shoe member will thus be locked together against lengthwise separation. During this operation, the springs F and G are forcibly flexed from their inclined positions to the righted positions shown in Figure l to exert lateral inward pressure on the posts and shoe member to force the friction surfaces of the posts into tight frictional contact with the friction surface of the shoe member. As wiil be evident, the stop lugs l !l and 2l-2l prevent rotation of the springs F and G, thus maintaining the same in proper position to press the posts against the shoe member.

My improved shock absorber preferably replaces one or more of the spring units of a truck spring cluster, being interposed between the usual top and bottom spring plates, which cooperate with said cluster.

The operation of the improved shock absorber is as follows: Upon the cluster of springs of the truck of a railway car being compressed between the spring follower plates of the cluster, my improved shock absorbing unit, which is disposed between the follower plates, is compressed with the springs, thereby forcing the post C downwardly toward the post D against the resistance of the springs F and G, the friction surface of the post C sliding on the friction surface 22 of the shoe member and the friction surface 22 of the shoe member sliding on the friction surface of the post D. Due to the canting tension of the springs F and G, the parts are held in tight frictional contact during this relative movement of the same, thereby providing the desired frictional resistance between the shoe member and the two posts.

Upon release of the mechanism the posts C and D are restored to the normal position shown in Figure l by the expansive action of the springs F and G, longitudinal separation of the parts being limited by engagement of the stop lugs l2-i2 of the posts with the stop shoulders 24-24 of the shoes.

I claim:

1. In a friction shock absorber, the combination with top and bottom friction posts relatively movable toward and away from each other; of an intermediate friction shoe with which said posts have longitudinal sliding engagement; and top and bottom springs reacting between said shoe and said top and bottom posts, respectively, yieldingly opposing relative lengthwise movement of the posts toward each other, said springs being canted to exert lateral inward pressure on said posts and shoe to force the same together.

2. In a friction shock absorber, the combination with a top friction post; of a bottom friction post, each of said Posts having a lengthwise extending friction surface, the friction surfaces of said posts facing in the direction; an intermediate friction shoe having a lengthwise extending friction surface thereon in sliding engagement with the friction surfaces of said posts; a top spring opposing relative movement of the shoe and top post toward each other; and a bottom spring opposing relative movement of said shoe and bottom post toward each other, said top and bottom springs being canted to exert lateral inward pressure on said posts and shoe.

3. In a friction shock absorber, the combination with a top follower; of top friction post depending from said top follower; a bottom follower; a bottom friction post upstanding from said bottom follower; an intermediate friction shoe provided with a follower member between its upper an lower ends, said shoe and posts having cooperating, lengthwise extending friction surfaces; a top spring surrounding said top post and hearing at its top and bottom ends on said topfcllower and follower member of the shoe, respectively; a 'bottom spring surrounding said bottom post and bearing at its top and bottom ends on said follower member of the shoe and said bottom follower, said top and bottom springs being canted to exert lateral inward pressure on said posts and shoe.

.1.. In a friction shock absorber, the combination with a top friction post having a laterally outwardly facing abutment surface on the outer side thereof at one side of the mechanism; of a bottom friction post having a laterally outwardly facing abutment surface at the outer side thereof at said side of the mechanism; an intermediate friction shoe having lengthwise sliding engagement with the inner sides of said posts, said shoe having upper and lower, laterally outwardly facing abutment surfaces at the opposite side of the mechanism; a helical coil spring under canting tension surrounding said top post and opposing relative lengthwise movement of said post and shoe toward each other, said spring having the inner sides of the coils at the top and bottom ends in bearing engagement respectively with the abutment surface of said top post and the top abutment surface of said shoe; and a second helical coil spring under canting tension surrounding said bottom post and opposing relative longitudinal movement of said post and shoe toward each other, said last named spring having the inner sides of the coils at the top and bottom ends in bearing engagement, respectively, with the bottom abutment surface of said shoe and the abutment surface of said bottom post.

5. In a friction shock absorber, the combination with a top follower plate; of a bottom follower plate; a top friction post depending from said top plate; a bottom friction post upstanding from said bottom follower plate; an intermediate friction shoe with which said posts have lengthwise sliding frictional engagement, said top post having a base portion presenting a lateral abutment surface, said bottom post having a base portion presenting a lateral abutment surface; a laterally projecting follower flange on said shoe between the upper and lower portions thereof, said upper portion of the shoe having a base portion presenting a lateral abutment face, said lower portion of the shoe having a base portion presenting a lateral abutment face; a coil spring under tension in canting direction enclosing said top post and bearing at its top and bottom ends on said top follower plate and the upper side of the follower flange of the shoe, said spring having the inner sides of the top coil thereof bearing on the outer side of the base portion of said top post at one side of the mechanism and the inner side of the bottom coil bearing on the base portion of the upper portion of said shoe at the opposite side of the mechanism; and a second coil spring under tension in canting direction enclosing said bottom post and bearing at its top and bottom ends, respectively, on the underneath side of the follower flange of said shoe and the bottom follower, said spring having the inner side of the top coil thereof bearing on the outer side of the base portion of said bottom post at said first named side of the mechanism and the inner side of the upper coil bearing on the base portion of the lower portion of said shoe at the opposite side of the mechanism.

6. In a friction shock absorber, the combination with top and bottom friction posts relatively movable toward and away from each other; of an intermediate friction shoe with which said posts have lengthwise sliding engagement; stop lugs on said post engageable with stop shoulders on said shoe for limiting lengthwise expansion of the mechanism; and top and bottom coil springs reacting between said shoe and said top and bottom posts, respectively, yieldingly opposing relative lengthwise movement of said posts toward each other, said springs being canted to press laterally inwardly on said shoe and posts to hold the same in tight frictional contact with. each other.

GEORGE E. DATH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS- 

